1. Field of the Invention
The present invention is a fluid filter cartridge, manifold and method for their assembly and for replacing cartridges.
2. Related Art
Fluid filters, particularly water filters, are known. Drinking water filters adapted for use with plumbing in buildings where people work or live is common in many areas. A variety of filter types can be used, including charcoal, other granular types of filters or pleated membranes and the like. After any filter has been used for a period of time, it becomes less effective as impurities build up within it. Accordingly, filter systems need to provide for filter replacement.
U.S. Pat. No. 5,336,406 to Stanford et al. is typical of a prior art filter system having a replaceable cartridge. One problem addressed by the Stanford patent is to prevent leakage of water during the replacement of a filter and/or a cartridge containing the filter. The Stanford reference discloses a spring loaded check valve for closing a water source pipe when a cartridge is removed from a manifold that holds it when in use. However, the prior art leaves unaddressed multiple continuing problems. For example, in the Stanford patent, only the water intake is stopped by the valve during replacement. There is a need in the art for stopping not only pressurized water inflow during cartridge replacement but also back flow from the water outlet side of the manifold.
Another continuing need in the art is protecting filter components from damage or misalignment during installation. For example, the filters themselves within cartridges typically have an outlet tube or other extension designed to engage an outlet in the manifold. Filters, filter outlet tubes, seals, O-rings and the like can all be damaged or misaligned during installation when prior art designs are used. There is a continuing need in the art for a more durable design for a cartridge closure member and its seating within a manifold receptacle for it.
Leakage of fluid during cartridge replacement is increased by the failure of the prior art designs to relieve input fluid pressure on closure components during cartridge replacement, particularly in relation to outflow pressure release. Leakage would be reduced and water pressure shock to a new filter is also reduced by providing pressure release through a fluid outlet sequentially with re-pressurization through a fluid inlet. However, no existing system achieves this.
There also remains a continuing need to avoid further damage or misalignment by a users repeated manual adjustment of the cartridge within the manifold caused by the users' inability to determine when a cartridge closure member has been properly seated in the manifold. There further remains a need for an ergonomically designed cartridge having a shape making it intuitively clear to a user how a cartridge properly seats in a manifold.
There is also a need in the art for allowing a user the option of replacing an entire cartridge, or simply a filter within the cartridge.
There is a continuing need in the art for a manifold and cartridge assembly easily assembled with existing plumbing, as for example, with manifold inlet and outlets being in line.
There are also continuing fluid flow optimization needs in the art. Designing the cartridge and filter assembly so that the intake of pressurized water does not misalign a filter within the cartridge, and so that distribution of incoming water to be filtered around all surfaces of the filter, in order to maximize its efficiency, is maintained.